Collared Stems Are Associated With Reduced Early Aseptic Loosening and All-Cause Revision Rate

Area of Science:

• Orthopedic Surgery
• Biomedical Engineering
• Arthroplasty Design

Background:

• The biomechanical benefits of collared femoral stems in total hip arthroplasty (THA) are debated.
• This study evaluates the survival rates of collared versus non-collared stems in primary THA.

Purpose of the Study:

• To compare the long-term survival of collared versus non-collared cementless femoral stems in primary THA.
• To investigate the association between femoral stem collar design and revision risk for aseptic femoral loosening (AFL) and all-cause revision.

Main Methods:

• Retrospective registry analysis of 168,493 primary THAs (2012-2024) in patients aged ≥ 50 years.
• Comparison of 25,066 collared stems versus 143,427 non-collared stems.
• Kaplan-Meier survival analysis and Cox proportional hazards models up to 10-year follow-up, adjusting for covariates.

Main Results:

• Collared stems showed significantly higher 10-year survival rates for both AFL (99.3% vs. 98.9%) and all-cause revision (96.8% vs. 95.3%).
• Adjusted analysis revealed collared stems were associated with a 42% reduced risk of AFL revision (HR 0.58) and a 35% reduced risk of all-cause revision (HR 0.65).

Conclusions:

• Collared femoral stems demonstrate superior survival outcomes in primary THA compared to non-collared designs.
• The use of collared stems is associated with significantly lower rates of aseptic loosening and revision.
• Collared stems may be a favorable option for improving THA outcomes in osteoarthritis patients.